Artificial hand



W. BAEHB.

ARTIFICIAL HAND.

APPLICATION FILED JULY 2,1919.

1,323,671Q Patented Dec. 2,1919.

ITNESSES. I/NVENTOQ 60134 W m. MM,

' Tom/Ev are adapted to 'Fig. 3 is a vertical sectional Th1 unibh ARTIFICIAL HAND.

' Application filed To all whom it may concern:

Be it known that I, WILLIAM BAEHR, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Artificial Hands, of which the following is a description, reference being had to the accompanying rawings, which are a part of this specification.

The invention relates to an artificial hand, more particularly of the type in which the hand is used on an arm having a stump below the elbow joint.

' One of the objects of this invention is to provide an artificial hand in which the jaws hold either flat. or round objects and is particularly useful to workmen to enable them to use various tools.

A further object of the invention is to provide an artificial hand in which the jaws may be turned with respect to their support and adjustably secured in turned position to facilitate handling objects.

The invention further consists in the several features hereinafter set forth and more particularly defined b claims at the con clusion hereof.

In the drawings:

Figure 1 is a side elevation view of the device embodying the invention; Fig. 2, is a section taken on the line 2-2 of Fig. 1;

' viewthrough the hand; Fig. 4 is a front end view of the hand.

The hand is secured to the arm by a sleeve member 5, stump socket 6, and a connection between the sleeve and the socket consisting of sets of metal hinge straps 7 and 8, the members of each set being hingeably secured together by a pivotjoint 9 adjacent the elbow joint of the arm. The sleeve 5 consists of a leather or fabric casing secured to the upper portion of the arm by lacing 10 and the straps 7 are riveted or otherwise suitably secured to saidsleeve on opposite sides thereof, only one of said straps being shown. The socket member 6 may be of fabric, leather or other suitable material and is adapted to receive the stump of the injured arm,

of the socket, only one of said straps being shown. The straps 8 are integral with or secured to a solid base portion 11 at the lower end of the socket, and the hand is removably secured to this base portion 1n Specification of Letters Patent.

holes in the socket member as and the straps 8 are.r1veted or,

otherwise suitably secured to opposite sides Patented lDec.2, 1919.

July 2, 1919. Serial No. 308,069,

a well known manner, which consists in providing the base 12 of the hand with a pin 13 having a groove 1 1 therein into which a spring locking device, of well known construction, upon the socket member engages, the base 12 also being provided with a pin 15 to engage in any one of a series of is usual to prevent turning of the base with respect to the socket.

The base 12 has an outwardly extending ball projection 16 to which the relatively fixedjaw 17'and the movable jaw 18 are connected. The jaw 17 is ofpeculiar channel shaped construction, having side portions 17 which taper upwardly from the front end and terminate in spherically curved portions 19 provided with slots 20, said curved portions fitting around the ball shaped end 16 of the base member 12, and an opening 21 is provided in said jaw so that the'handle of a tool such as a hammer, may be passed through said opening and grasped by the jaws.

The movable jaw member 18 is of a channel construction and the sides 22, together with the top 23 'at the rear end of the jaw, are sphericallycurved so as to fit over the spherically curved portions 19 of the fixed jaw, so that the movable jaw 18 will move toward and away from the fixed jaw even though the fixed jaw be turned to different ositions with respect to the base 12.

The jaws 17 and 18 are provided with cooperating sets of teeth to enable them to grasp and hold an article. The front tooth portions 24 of the jaws are adapted to register with each other, while the rear tooth portions 25 of the jaws are spaced away from each other, the arrangement providing for grasping articles of different shapes, and the front ends 26 of the jaws are curved to form an opening 27 to receive an object.

The ball shaped end 16 is provided with segmental slots. 28 meeting each other in the central portion of said ball shaped end and a pivot pin 29 is slidably mounted in these slots and passes through the slots 20 in the fixed jaw and through holes 30 in the movable jaw. Spherical clamping plates 31 and 32 are carried by the ends of the pivot bolt and the plate 32 has a threaded opening engaging the threaded end 33 of the pivot bolt and is provided with holes 34 so that a spanner wrench may be used to turn plate 32 on to the threaded end 38 of the pivot 40 7 other object may b'e inserted between the bolt and thus clamp the jaws 18 and 17 to the ball shaped end 16 at the base of the hand. This construction provides for turning the jaws with respect to the base of the hand to its angular positions and when adjusted the jaw 17 is relatively fixed and the 'jaw 18 is adapted to swing about this pivotand to accomplish this the inner faces of the portions 19 and the outer faces of the ball 16 are roughened and the inner faces of the plates 32 and 31 and the outer faces of the portion 23 of the jaw 18' are roughened,

while the inner faces of the portion 23 and the outer faces of the portions 19 are smooth,

so that on a clamping of the jaws to the 7 base in an adjusted position the jaw 18 may be moved on its pivot relatively to the jaw 17.

The movementof the jaw 18 s automatically accomplished on the movement of i the arm by means-of a strap 35 adjustably secured to the upper end of one of the metal straps 7 and provided with a fiexible'connection 36 which passes through a guide 37 on one of the strap members 8 adjacent the elbow joint 9 and carries a hook 38 engageable with an upstanding lug 39 on the jaw 18, said hook being adapted to be disengaged from said lug 39 when desired. A spring 40 is interposed between the base and the lug 39, the ends of the spring fitting around projections 41 on said base and lug, and the spring normally serving to maintain the jaws in closed position.

With this construction, when the wearer moves the lower end of the arm downwardly, as shown in dotted lines in Fig. 1, the pull exerted on the cord or flexible connection 36 will compress the spring 40 and move the aw 18 to open position, so that a tool or jaws, and when the arm is raised the tension on the connection 36 will be relieved and the spring will serve to clamp the tool or other object between the jaws. Also, by adjusting the pivotal connection of the jaws with the base, said jaws maybe set at different angles with respect'to the base for taking up the work. When desired, the connection 36 may be disconnected from the jaw 18 and the hand-removed and replaced by an end, of a relatively immovable artificial hand of well known construction.

What I claim as new and desire to secure by Letters Patent is:

1. In an artificial hand, the combination,

with a base member, of a relatively fixed jaw having an opening in its rear end to receive the handle of a tool and'a gripping surface at its forward end in line with said opening, a movable jaw having a gripping surface at its forward end cooperating with that of the fixed jaw, a spring for normally maintaining said movable jaw in clamping engagement with the fixed jaw, and means for automatically opening the jaws. V

2. In an artificialhand, the combination, with a base member having a ball shaped,

member, of a relatively fixed member hav ing spherically curved portions engaging said ball shaped end, a movable jaw having spherically curved portions engaging the spherically curved portions of the fixed j aw, means for securing said fixed jaw in difierent positions of adjustment'with respect to the base but permitting pivoted movement of the movable-j aw with respect to the fixed jaw, a spring normally maintaining said I aws closed, and means for automatically opening the jaws on the movement of the arm.

3. In an artificial hand, the combination, with a base member ball-shaped end, and

amovable jaw having spherically curved portions engaging the having a ball-shaped fixed member having spherically curved portions engaging said'g5" spherically. curved portions of the fixed j aw.

ing an opening in its rear end in line with.

, WILLIAM BAEHRQ 

